1. Field
Exemplary embodiments relate to a magnetic resonance imaging apparatus which includes a connector.
2. Description of the Related Art
In general, a medical imaging system is an apparatus that provides internal information about a patient as an image. Medical imaging systems include an X-ray machine, an ultrasonic diagnostic apparatus, a computer tomography scanner, a magnetic resonance imaging apparatus, etc.
A magnetic resonance imaging (MRI) apparatus holds an important position in the field of diagnostic technology using medical images, because the MRI apparatus functions under less stringent photographing conditions than other medical imaging apparatuses and provides superior contrast images of soft tissues and various diagnostic information images.
The MRI apparatus causes nuclear magnetic resonance in the hydrogen atomic nuclei of the human body by using a magnetic field which is harmless to humans and radio frequency (RF) energy which is non-ionizing radiation, to thereby image the densities and physical or chemical characteristics of the atomic nuclei.
In more detail, the MRI apparatus supplies energy which has a specific frequency and energy level to atomic nuclei in the state in which a constant magnetic field has been applied to the atomic nuclei, thereby causing the atomic nuclei to release energy, and converts the energy released from the atomic nuclei into signals, thereby facilitating a diagnosis of the inside of the human body.
When a magnetic field is applied to the atomic nuclei, protons configuring the atomic nuclei are arranged in the direction of the magnetic field since the protons have spin angular momentum and magnetic dipole moment, and the atomic nuclei perform precession with respect to the direction of the magnetic field. Precession causes nuclear magnetic resonance, through which an internal image of the human body is acquired.
The MRI apparatus applies a gradient field to a static field formed in a subject in order to acquire an image of the subject. The static field may be formed by a static coil unit. The gradient field may be formed by a gradient coil unit.
The gradient coil unit may be positioned inside the static coil unit. The gradient coil unit may include primary coils to generate a gradient field and shield coils to restrict generation of an eddy current.
Since a uniform static field should be formed in the subject, shims are provided for homogeneity of a static field formed by the static coil unit. The shims may be provided inside the gradient coil unit which forms a gradient field in a static field. If passive shims are used, the passive shims are configured with shim tokens and shim trays in which the shim tokens are accommodated.